It Wouldn't Hurt To Have a Little Sister
by KurohimePhantomlord
Summary: Three months have passed since Killua snuck in Kukuroo Mountain a small little mutant girl named Shiro Neko. As her name suggests, she has the qualities of a cat. Killua knows the risks of wanting to keep someone or something like her but he takes care of her anyway, thinking "it wouldn't hurt to have a little sister"


"It Wouldn't Hurt To Have a Little Sister"

Killua excitedly ran down the forest on the far side of Kukuroo Mountain. The weight of the backpack didn't slow him down, especially as he neared that certain spot. And upon nearing it, he suddenly recalls how this all began.

* * *

The reddish fluid colored the tattered carpet of a dark living room. Living? How ironic, given that he just killed everyone in there.

_I suppose that's it. Another assignment done effortlessly._ Killua sighed. _How boring._

Killua was supposed to kill a whole family of scientists who were rumored to be starting genetic mutations. The client thought of them to be a threat as he said that they would soon create an army of mutants to kill everyone in the city. Of course, this doesn't matter to Killua and he didn't find any mutants either (although he thought it would have been terrifyingly awesome).

The Zoldyck prodigy was about to leave when he heard a noise coming from the small door underneath the wooden floor where the corpse of a teenage girl in a lab coat lies. Killua raised an eyebrow and cautiously approached it. He doesn't sense any danger but it was better to be safe. When he got to the corpse, he kicked it aside and that's when the noise ceased. Killua analyzed the situation and thought if it would be wise to open the door but there was no need as it slightly opened on its own. Killua backed away as the creature's sparkly blue eyes looked around the room then landed on him. The opening got wider and the creature climbed out. Killua slightly relaxed as it was only a little girl who seems four years younger than him. She has long, straight, snow-white hair, a light complexion and big blue eyes which looked at him fondly. She was wearing a miko outfit which reminded him of his sister, Alluka, and this made his supposed urge to kill her waver. Killua shook his head.

_What are you doing, baka? You should get this over with. Kill her and go home. _

"Onii…-chama?" the girl called, tilting her head to the side and making Killua's eyes widen.

_Crap. That's not good._

Killua poised prepared his claws for the kill but as he looked at the little girl with his cold, hard assassin eyes, she looked back at him innocently with her bright blue ones.

After seconds of staring, Killua gave up. He dropped his hand to his side, sighed and casually walked towards the little girl.

"Oy!" Killua placed his hand on her head but his eyes widened when he realized something.

_She has cat ears?!_

Killua was about to back away when the girl nudged his hand, making him ruffle her hair a little.

"You're my onii-chama!" the girl exclaimed and nudged Killua's shirt.

"O-oy!" Killua's not one to hug strangers, even if they're that cute.

The little girl pouted and looked at him with watery eyes. "Onii-chama… is mad?"

Killua reacted like how any person would when they made a little kid, especially a girl, cry. "H-hey! Don't cry! It's fine!"

Killua patted the girl's head and caressed her hair. The little girl stopped sniffling and suddenly hugged Killua, burying her face in his chest.

"Onii-chama…" She shook her head.

Killua, who was bewildered at first, softened and hugged her back.

_Well… We both have white hair… and blue eyes… and she sort of reminds me of Alluka. _Killua smiled and tightened his embrace. _Well, I suppose it wouldn't hurt to have a little sister_

* * *

Killua stood before the small hut he built himself. It was built right beside a small waterfall with a river connected to a much bigger waterfall at the other side of the mountain. Only Killua knows this spot and he decided to share it with his new little sister.

"Neko! I'm here!" Killua called. "I brought your favo-ah!"

Killua was caught by surprise as Shiro Neko stealthy glomped him.

"Onii-chama!" Shiro Neko giggled and cuddled her white-haired brother.

"Neko, it's 'onii-sama'" Killua laughed a little and sat up. Neko sat up as well. "Anyway, I brought your favorite!"

As Killua lifted the bag, Neko raised her eyebrow.

Killua rolled his eyes. "And it's not poisoned. I've tested it."

The first time Killua brought sweet buns to Neko, they were actually poisoned. It was a good thing the poison wasn't so strong and Neko's immune system was outstanding so all Neko got was a tummy ache that no herb can't remedy. Still, despite that supposed traumatizing experience, she loves the creamy filled buns.

Neko's eyes sparkled as she took the bag from Killua and rummaged through it, pulling out sweet bun after sweet bun after eating one. Before long, her face and hands were caked with cream. Killua laughed.

"Honestly" Killua shook his head. "You should eat neater. Come on, let's wash off the cream."

Neko grinned and she walked to the small river with Killua. She soaked her hands in the cold water and Killua, having expected it, brought a towel with him. He soaked part of it and began wiping the cream off of Neko's face.

"Now, let's dry your hands" He said, extending the dry part of the towel. Neko submissively extended her hands. As Killua dries them, he couldn't help but notice the partial scars peeping out of her sleeves. He's seen them over and over but he couldn't help but condemn those scientists he killed three months ago.

_I curse those scientists who tortured you… It really feels good… that I was the one who killed them… and saved you._

"Um… Onii-… chama? My hands are dry now." Neko's voice woke Killua from his reveries.

"Huh? Oh. Sorry, Neko." Killua was absentmindedly wiping Neko's now dry hands, as though caressing them to make the scars disappear.

He withdrew his hands from hers and walked back to his bag.

"I brought you new clothes and a blanket. I got them from my last mission. I passed by a store and thought it would be nice for you to have them." Killua gestured for Neko to follow him inside the hut and she obediently did so.

Once inside, Killua laid out all the new kimonos and colorful blanket for Neko.

"Woooow! Thank you so much, onii-chama!" Neko flung her arms around Killua's neck. "Onii-chama is the best! He never hurts Shiro Neko and always cares for her!" Neko cuddles Killua.

Killua has gotten used to Neko's sweetness so he hugged her back. "No problem, imouto-chan"

Killua then smirked and let go of Neko which caused her to let go too and look at him a little puzzled because of his smirk. And from his pocket, he produced catnip. Neko's eyes lit up and the muscles in her body tensed. Killua sensed it and grinned. He stood up and quickly went outside where Neko started chasing him and reaching for the catnip.

Until sunset, Killua and Neko played.

"Ahhh!" Killua sighed of relief as he sat down on the ground. "That was a good exercise"

Neko sat beside him, eyeing the catnip in Killua's hand from time to time.

"Hey, Neko?"

"Yes, onii-sama?" Neko's attention turned fully to Killua.

"I'm going on another mission tomorrow." Killua looked at Neko who is now pouting at him.

"Onii-chama is going to leave again, huh?" Neko looked away from Killua to the sunset ahead of them.

Killua was silent and looked at Neko, her face bathed in orange light.

"I'll be back. You know that." Killua looked off into the sunset as well.

"I know… Onii-chama is the best assassin ever. When you get back, let's play again, ne?" Neko looked at Killua and smiled.

Killua looked back at her and smiled back. "Of course, Neko. Of course." And he ruffled her hair, making her giggle. Killua rose and Neko watched as he took his bag and walked to the woods. Killua took one last glance as Neko and they smiled at each other. He then disappeared into the trees, leaving Neko.

Neko looked at the sunset again and sighed. She remembered how Killua sneaked her in by fitting her into his bag. He emptied his stuff somewhere so Neko will fit perfectly inside. She also remembered the first time Killua left her and didn't come back for days. She wandered the forest in search of him and was surprised to see him suddenly who was also very surprised to see her. It was the first time she saw him so worried about her that he embraced her tightly. After that, Killua would always tell her if he was going on a mission so she doesn't wander off again and encounter "people you wouldn't want to meet", as he would say.

"Onii-chama" Neko hugged her knees and watched the sunset's reflection in the water.

* * *

The mission only lasted for three days but Killua couldn't help but feel so worried about leaving Neko again. Why should he be worried? He's been leaving her to do his missions a lot of times now though it's been more recent now. She doesn't wander off anymore and she's always been a good girl, waiting for him inside the hut or something that won't get her into trouble. But why now? Why does he feel so worried? The airship he boarded is close to its destination and he can just walk all the way to the mountain. He's just going to report to his mother or father or grandfather then he's off to see Neko again. So why are his palms sweating so much?

Killua was now walking through the intimidating halls of the Zoldyck mansion. He was on his way to his father's room. When he got there, just about every member of the family is except for his mother and Kalluto.

"Welcome back, Killu" greeted Illumi.

Killua nodded.

"So how did it go?" asked Zeno.

Killua was about to start when the door burst open, making every eye in the room shift their gaze, to reveal Kikyo and with her was Kalluto and…

_Neko?! _Killua's eyes widened

Killua's mother who was dragging Neko by her long white hair, threw her to the ground. Poor Neko, wearing a cute pink kimono with cherry blossom prints- one among Killua's gifts- and was so eager to see Killua again, was covered in blood and was barely breathing.

"Kikyo, what's the meaning of this? Who is that?" When Silva saw the cat ears, "WHAT is that?"

"An intruder. I saw her when Kalluto and I passed by a small waterfall that we stumbled into." Kikyo answered. "I don't know how she got in here but the thing's almost dead. I just came to show you. " Her attention shifted to her son. "Killu! You're back!" She ran to embrace him but he looked at her with his cold eyes which made her stop in her tracks. "Killu?"

"O-Onii...-sama…" Killua's now surprised gaze shifted to Neko who smiled a little as she weakly looked at Killua. "I finally got it… right"

Neko closed her eyes with a slight smile on her lips. Killua bit his lower lip and quietly left his father's room and went to his, his thoughts swirling like a whirlpool on the way.

_Neko… That was Neko… She was covered in blood… Mother found her… She's dead because of me… Because I left her… I shouldn't have left her… Maybe I shouldn't have adopted her… I knew it was dangerous… That's why…_

Killua's thoughts went back to when he was walking away from Neko before leaving for his mission, _When I come back, Neko… I won't just play with you… We'll run away… Live in a peaceful town and I can earn more money in Heaven's Arena… We can live… just the two of us… and if anyone teases you or makes fun of you, I'll make sure they regret it…_

Killua arrived in his room. He locked the door and there, the tears fell… the spot where he bit his lip started bleeding.

_Now, I can't protect you anymore… I can't pat you on the head nor can I hold you in my arms and tell you how much I love you or how much I'm thankful that you're my sister… You always made me forget the things going on inside our house… inside this insane household. Just your smile is enough to lift the burden off my shoulders… I never thought… it would hurt this much to lose a little sister…_


End file.
